System and method for separating battery cell cores

ABSTRACT

The system for separating battery cell cores includes a cell core holder for receiving and holding a battery cell core. A cutter cuts an outer wrapping layer of the battery cell core to form an open loose end. A first roller rotates the battery cell core and a sheet opener engages the open loose end to unroll a laminate, which includes a cathode layer, an anode layer, and a polymer separator layer sandwiched therebetween. A pair of second rollers receive, grip and selectively drive movement of the laminate. A cathode breaker applies breaking force to the cathode layer to produce broken cathode layer pieces, which are then collected. An anode breaker then grasps and vibrates the laminate to produce broken anode layer pieces, which are also collected. Finally, a polymer separator layer cutter selectively cuts the polymer separator layer to produce cut polymer separator layer pieces, which are collected.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/604,775, filed on Jul. 21, 2017.

BACKGROUND 1. Field

The disclosure of the present patent application relates to therecycling of batteries, such as conventional lithium ion rechargeablebatteries, for example, and particularly to a system and method forseparating cell cores of such batteries into their individual cathodefoil, anode foil and polymer separator layers.

2. Description of the Related Art

Lithium ion batteries are a very common type of rechargeable battery.The disposal and recycling of lithium ion batteries is of considerableinterest, since such batteries not only contain valuable materials, butalso contain materials which are quite hazardous, both to human beingsand the environment. Prior to any chemical recycling process, such as,for example, hydrometallurgical or pyrometallurgical processes, in orderto extract the valuable materials from the batteries (e.g., cobalt,lithium, copper, etc.), the batteries must first be safely disassembled,and the various material components must be carefully separated.Following removal of the outer metal casing, the remaining “cell core”must be broken down.

Conventional processes for breaking down cell cores typically involvebreaking the cell core into small pieces, followed by extraction of thevaluable metals from the resultant mixture. The separation process,however, is quite difficult, since the cathode and anode powders aremixed together. It would obviously be desirable to be able to easilybreak down battery cell cores while keeping the cathode layer, anodelayer and polymer separator layer separate from one another. Thus, asystem and method for separating battery cell cores solving theaforementioned problems is desired.

SUMMARY

The system for separating battery cell cores includes a cell core holderwhich is sized and shaped for receiving and holding a battery cell core.A loader, such as a ramp or the like, is coupled to the cell core holderfor transferring the battery cell core to the cell core holder. A cutteris positioned adjacent the cell core holder for cutting an outerwrapping layer of the battery cell core to form an open loose end. Afirst roller selectively rotates the battery cell core within the cellcore holder, and a sheet opener engages the open loose end of thebattery cell core to unroll a laminate of the battery cell core. Thelaminate includes a cathode layer, an anode layer, and a polymerseparator layer sandwiched therebetween. For example, for a conventionallithium ion battery, the cathode layer may include a relatively brittlealuminum foil, the anode layer may include a copper foil, and thepolymer separator layer is positioned between each layer forelectrochemical separation thereof.

A pair of second rollers receive, grip and selectively drive movement ofthe laminate. The pair of second rollers applies pressure to therelatively brittle cathode layer, providing an initial break forcetherefor, and a cathode breaker applies additional breaking force to thecathode layer of the laminate to produce broken cathode layer pieces. Acathode layer collection box is provided for receiving the brokencathode layer pieces.

An anode breaker then grasps and vibrates the laminate to produce brokenanode layer pieces, which are collected in an anode layer collectionbox. Finally, a polymer separator layer cutter selectively cuts thepolymer separator layer of the laminate to produce cut polymer separatorlayer pieces, which are then collected in a polymer separator layercollection box. A flap is provided for selectively covering the polymerseparator layer collection box. The flap is selectively angled, thusproviding a ramp-like surface, when the flap is closed, for directingthe falling pieces into either the cathode layer collection box or theanode layer collection box. When the flap is opened, the cut pieces ofthe polymer separator layer may freely fall into the polymer separatorlayer collection box and are prevented from entering either the cathodelayer collection box or the anode layer collection box.

These and other features of the present disclosure will become readilyapparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 diagrammatically illustrates a system for separating battery cellcores.

FIGS. 2A, 2B and 2C sequentially illustrate unrolling of a three-layerlaminate from a battery cell core as implemented by the system forseparating battery cell cores.

FIG. 3A diagrammatically illustrates a first stage of operation of acell core layer separation mechanism of the system for separatingbattery cell cores in which a cathode layer of the laminate is separatedand collected.

FIG. 3B diagrammatically illustrates a second stage of operation of thecell core layer separation mechanism of the system for separatingbattery cell cores in which an anode layer of the laminate is separatedand collected.

FIG. 3C diagrammatically illustrates a third stage of operation of thecell core layer separation mechanism of the system for separatingbattery cell cores in which a polymer separator layer of the laminate iscut and collected.

FIG. 4 diagrammatically illustrates an alternative embodiment of thesystem for separating battery cell cores.

Similar reference characters denote corresponding features consistentlythroughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, the system for separating battery cell cores 100receives untreated cell cores C via a loader 102. Although only a singleuntreated cell core C is shown in FIG. 1, it should be understood thatmultiple untreated cell cores C may be queued for individual release.The untreated cell core C may be, for example, the core of a lithium ionbattery; i.e., a lithium ion battery in which the outer protective metalshell has already been removed. Loader 102 transfers the untreated cellcore C to cell core holder 103. Although shown as a simple ramp whichallows the untreated cell core C to roll into cell core holder 103 underthe force of gravity, it should be understood that any suitable type ofloading mechanism may be used to load the untreated cell core C intocell core holder 103.

Cell core holder 103 is preferably contoured and sized to fix theposition of the untreated cell core C. It should be understood that thecontouring and relative dimensions of cell core holder 103 are shown inFIGS. 1 and 2A-2C for exemplary purposes only. An additional grabbing orgrasping system 104 may be provided for secure holding of the untreatedcell core C. For example, grabbing or grasping system 104 may include apair of needles which are diametrically opposed, with respect to theuntreated cell core C, and which pierce the untreated cell core C. Thegrabbing or grasping system 104 may then be used to not only secure theuntreated cell core C in place, but further selectively rotate theuntreated cell core C. The rotation may be driven by a conventionalmotor or the like.

As best shown in FIGS. 2A and 2B, a cutter 105 is used to open thewrapping layer of the untreated cell core C. The cutter 105 may be aknife, a needle, a laser or the like. It should be understood that thenon-limiting example of a blade, shown in FIGS. 2A and 2B, is shown forexemplary purposes only. As seen in FIG. 2B, the exemplary blade ofcutter 105 is driven by a linear actuator, motor or the like to cut theouter plastic wrapping layer of the untreated cell core C to form anopen loose end; i.e., cutter 105 makes an axial cut in the outer plasticwrapping layer. It should be understood that cutter 105 may cut morethan only the outer wrapping layer; i.e., additional layers inside thecell core C may also be cut. In this case, the portion removed with theouter wrapping layer is considered to be waste material and isdiscarded, along with the outer wrapping layer. The remainder of theprocess, as described in detail below, is then followed.

Following formation of the cut in the outer plastic wrapping layer, thecutter 105 returns to its initial standby position, as shown in FIG. 2C.The grabbing or grasping system 104 and/or an assistant roller 107, eachdriven by a motor or the like, rotate the untreated cell core C suchthat the open loose end of the untreated cell core C is directed towarda sheet opener 106.

As shown in FIG. 2C, the sheet opener 106 unrolls the untreated cellcore C into a laminate L of its three constituent layers, namely,cathode layer 202, anode layer 206, and polymer separator layer 204. Asshown in FIGS. 1 and 3A, following unrolling by the sheet opener 106,the laminate L is directed towards cell core layer separation mechanism109 by directing plate 108. In FIGS. 1 and 2A-2C, sheet opener 106 isshown as a bladed cutting element. It should be understood that theblade of sheet opener 106 is shown as a non-limiting example only inFIGS. 1 and 2A-2C, and that sheet opener 106 may be any suitable type ofplate or other member which can open the cell core C at the location cutby cutter 105.

With reference to FIG. 3A, laminate L is fed, under guidance bydirecting plate 108, between a pair of rollers 302. It should beunderstood that the contouring and relative dimensions of directingplate 108 are shown in FIG. 1 for exemplary purposes only. Preferably,as shown, a first sensor 210 is positioned adjacent rollers 302,allowing the rollers 302 to be automatically activated when laminate Lis detected. Rollers 302 act to not only pull laminate L downward, butthe pressure exerted thereby on laminate L acts to break the relativelybrittle cathode foil 202 (typically formed from brittle aluminum foil).

In addition to the pressure exerted by rollers 302, a cathode breaker303 is provided for continuously tapping laminate L to further break thecathode foil 202 into pieces. Although shown in the form of apendulum-type tapping mechanism, it should be understood that cathodebreaker 303 may be any suitable type of mechanism for exerting abreaking force to the cathode foil 202. Since the aluminum cathode foilused in conventional lithium ion batteries is much more brittle than theconventional copper anode foil and the conventional polymer separatorlayer, the forces exerted by the rollers 302 and the cathode breaker 303will break the aluminum foil 202 (containing cathode powders) into smallpieces. These pieces will then fall into cathode layer collection box305 under the force of gravity. In the non-limiting example ofpendulum-type tapping cathode breaker 303, a periodic force, in the formof periodic taps or pulses, is delivered to cathode layer 202.

As shown, a cathode layer collection box 305, a polymer separator layercollection box 309 and an anode layer collection box 307 are eachprovided, with the polymer separator layer collection box 309 beingsandwiched between cathode layer collection box 305 and anode layercollection box 307. In the initial stage of FIG. 3A, a flap 304 coversthe a polymer separator layer collection box 309 and is angled such thatthe falling pieces only fall into cathode layer collection box 305. Itshould be understood that cathode layer collection box 305, polymerseparator layer collection box 309, anode layer collection box 307 andflap 304 are each illustrated diagrammatically for purposes ofillustration only, and that each may have any suitable size, contouringand relative dimensions. Further, as will be described in greater detailbelow, flap 304 is selectively opened and closed as well as beingselectively angled. The movement of flap 304 may be driven by anysuitable type of motor, linear actuator or the like. It should beunderstood that the particular arrangement of cathode layer collectionbox 305, polymer separator layer collection box 309 and anode layercollection box 307 is shown as a non-limiting example only, and that anydesired arrangement thereof may be utilized. For example, rather thanpositioning cathode layer collection box 305 on the left (as in theexemplary arrangement of FIGS. 3A-3C), the cathode layer collection box305 could be placed in the middle, between polymer separator layercollection box 309 and anode layer collection box 307. Where theparticular pieces fall from the laminate is controlled by motion of theflap 304, thus, under the control of flap 304, any desired positioningof the collection boxes may be utilized.

When the lower end 214 of laminate L is detected by a second sensor 212,located just above the collection boxes 305, 307, 309, the rollers 302stop. It should be understood that first and second sensors 210, 212 maybe any suitable type of sensors, such as photodetectors, mechanicalswitches or the like. At this point, as shown in FIG. 3B, an anodebreaker 306, which may include a pair of horizontally translatingmembers, as shown, grasps laminate L. The anode breaker 306 thenvibrates horizontally to break up the copper foil layer 206 (containinganode powders), and these broken pieces drop into the anode layercollection box 307. The cathode breaker 303 may continue its tappingmotion to assist the breakage of anode layer 206. In the second stage ofFIG. 3B, flap 304 covers the polymer separator layer collection box 309,but is angled in a direction opposite to that of FIG. 3A. Thus, thefalling pieces in the second stage only fall into anode layer collectionbox 307.

As shown in FIG. 3C, once the copper foil has been collected, a polymerseparator cutter 308 moves in to cut the polymer separator layer 204,which is collected in the polymer separator layer collection box 309.Although polymer separator cutter 308 is shown in FIGS. 3A-3C as ahorizontally translating blade, it should be understood that this is anon-limiting example only, and that polymer separator cutter 308 may beany suitable type of cutting element or device for cutting or severingpolymer separator layer 204. In this third stage, flap 304 is open abovethe polymer separator layer collection box 309. As shown, flap 304 maybe a two-piece flap, allowing for the configurations shown in FIGS. 3A,3B and 3C, where each of the two pieces of flap 304 are verticallyoriented in FIG. 3C, preventing any of the falling pieces from fallinginto either cathode layer collection box 305 or anode layer collectionbox 307. As shown, in the third stage, anode breaker 306 continues tograsp the laminate but no longer vibrates. Following the third stage,polymer separator cutter 308 returns to its initial standby positions.

It should be understood that the cell core layer separation mechanism109 can be designed to cut the laminate L in one round or in multiplerounds, depending on the size of, and available space for, the systemfor separating battery cell cores 100. For a configuration in whichlaminate L is cut in a single round, the cell core layer separationmechanism 109 must be sufficiently long. For a typical cell core, thecell core layer separation mechanism 109 would have a length betweenapproximately 1.0 and approximately 1.5 m. For a configuration in whichthe laminate L is cut in multiple rounds, the actions described abovewould be repeated multiple times. Once the polymer separator layer 204has been cut, the cell rollers 302 are activated again to move the nextportion of the laminate L downward. The above process is then repeatedfor each segment of laminate L.

As shown in FIG. 4, an additional cathode breaker 216 may be added, ifnecessary, for providing additional breaking force to laminate L beforeit enters rollers 302. In this alternative embodiment, rather thandirectly entering into the cell core layer separation mechanism 109, thelaminate L is first continuously tapped by the additional cathodebreaker 216 to break the aluminum cathode layer 202 into pieces. Theprocess then proceeds as described above, where further breaking bycathode breaker 303 is more easily implemented. In this embodiment, itshould be understood that additional components for assisting the fallof pieces broken by additional cathode breaker 216 may be added. As anon-limiting example, a fan or blower may be provided to blow thedetached pieces of cathode foil down the directing plate 108 if they donot move down the directing plate 108 on their own (or under the drivenmotion of laminate L).

It is to be understood that the system and method for separating batterycell cores is not limited to the specific embodiments described above,but encompasses any and all embodiments within the scope of the genericlanguage of the following claims enabled by the embodiments describedherein, or otherwise shown in the drawings or described above in termssufficient to enable one of ordinary skill in the art to make and usethe claimed subject matter.

We claim:
 1. A system for separating battery cell cores, comprising: a cell core holder adapted for receiving and holding a battery cell core; a cutter for cutting an outer wrapping layer of the battery cell core to form an open loose end; a first roller for selectively rotating the battery cell core within the cell core holder; a sheet opener for engaging the open loose end of the battery cell core to unroll a laminate of the battery cell core, the laminate having a cathode layer, an anode layer, and a polymer separator layer sandwiched therebetween; a pair of second rollers adapted for receiving and selectively driving movement of the laminate; a cathode breaker for applying a breaking force to the cathode layer of the laminate to produce broken cathode layer pieces; a cathode layer collection box for receiving the broken cathode layer pieces; an anode breaker for grasping and vibrating the laminate to produce broken anode layer pieces; an anode layer collection box for receiving the broken anode layer pieces; a polymer separator layer cutter for cutting the polymer separator layer of the laminate to produce cut polymer separator layer pieces; and a polymer separator layer collection box for receiving the cut polymer separator layer pieces.
 2. The system for separating battery cell cores as recited in claim 1, further comprising a loader coupled to the cell core holder for transferring the battery cell core to the cell core holder.
 3. The system for separating battery cell cores as recited in claim 2, wherein the loader comprises a ramp.
 4. The system for separating battery cell cores as recited in claim 1, wherein the battery cell core is a cell core of a lithium ion battery.
 5. The system for separating battery cell cores as recited in claim 4, wherein the cathode layer comprises aluminum foil.
 6. The system for separating battery cell cores as recited in claim 5, wherein the anode layer comprises copper foil.
 7. The system for separating battery cell cores as recited in claim 1, further comprising a directing plate mounted between the sheet opener and the pair of second rollers for guiding the laminate to the pair of second rollers.
 8. The system for separating battery cell cores as recited in claim 1, wherein the cathode breaker applies periodic pulses of the breaking force to the cathode layer.
 9. The system for separating battery cell cores as recited in claim 1, further comprising a flap for selectively covering the polymer separator layer collection box.
 10. The system for separating battery cell cores as recited in claim 9, wherein the flap is selectively angled.
 11. A system for separating battery cell cores, comprising: a cell core holder adapted for receiving and holding a battery cell core; a loader coupled to the cell core holder for transferring the battery cell core to the cell core holder; a cutter for cutting an outer wrapping layer of the battery cell core to form an open loose end; a first roller for selectively rotating the battery cell core within the cell core holder; a sheet opener for engaging the open loose end of the battery cell core to unroll a laminate of the battery cell core, the laminate having a cathode layer, an anode layer, and a polymer separator layer sandwiched therebetween; a pair of second rollers adapted for receiving and selectively driving movement of the laminate; a cathode breaker for applying a breaking force to the cathode layer of the laminate to produce broken cathode layer pieces; a cathode layer collection box for receiving the broken cathode layer pieces; an anode breaker for grasping and vibrating the laminate to produce broken anode layer pieces; an anode layer collection box for receiving the broken anode layer pieces; a polymer separator layer cutter for cutting the polymer separator layer of the laminate to produce cut polymer separator layer pieces; and a polymer separator layer collection box for receiving the cut polymer separator layer pieces.
 12. The system for separating battery cell cores as recited in claim 11, wherein the loader comprises a ramp.
 13. The system for separating battery cell cores as recited in claim 11, wherein the battery cell core is a cell core of a lithium ion battery.
 14. The system for separating battery cell cores as recited in claim 13, wherein the cathode layer comprises aluminum foil.
 15. The system for separating battery cell cores as recited in claim 14, wherein the anode layer comprises copper foil.
 16. The system for separating battery cell cores as recited in claim 11, further comprising a directing plate mounted between the sheet opener and the pair of second rollers for guiding the laminate to the pair of second rollers.
 17. The system for separating battery cell cores as recited in claim 11, wherein the cathode breaker applies periodic pulses of the breaking force to the cathode layer.
 18. The system for separating battery cell cores as recited in claim 11, further comprising a flap for selectively covering the polymer separator layer collection box.
 19. The system for separating battery cell cores as recited in claim 18, wherein the flap is selectively angled.
 20. A method of separating battery cell cores, comprising the steps of: cutting an outer wrapping layer of a battery cell core to form an open loose end; rotating the battery cell core and engaging the open loose end of the battery cell core to unroll a laminate of the battery cell core, wherein the laminate includes a cathode layer, an anode layer, and a polymer separator layer sandwiched therebetween; applying a breaking force to the laminate to produce broken cathode layer pieces; collecting the broken cathode layer pieces; grasping and vibrating the laminate to produce broken anode layer pieces; collecting the broken anode layer pieces; cutting the polymer separator layer of the laminate to produce cut polymer separator layer pieces; and collecting the cut polymer separator layer pieces. 